January i6, 1896] 



NATURE 



255 



barrels take a charge of ten tons of ore, instead of only five. 

 The filter inside the barrel is retained, but the expensive asbestos 

 cloth, which lasted for only a few charges, is replaced by a 

 cheap sand-filter, which, it is stated, is not shifted by the rotation 

 of the barrel, and does not become clogged until after it has 

 been used for about loo charges, or say a month. While the 

 Americans are thus engaged in perfecting the barrel process, the 

 Australians have abandoned it altogether. At the Mount Morgan 

 Mine, where there is the largest chlorination plant in the world, 

 the vats have been reintroduced, but are much enlarged, each 

 having a capacity of twenty-five tons. Chlorine water is used, 

 the consumption of chemicals being less, and the reagent more 

 under controi than if gas is pumped into the charge. The use 

 of bleaching powder and sulphuric acid for generating the gas 

 I has been superseded again by manganese dioxide, salt and 



sulphuric acid, and the installation of chlorine stills, towers, and 

 solution tanks. The extraction of gold at Mount Morgan is 

 about 95 per cent, of the total amount in the ore, and the cost 

 of treatment, now about 155-. per ton, is expected to be reduced 

 to 12^. per ton by the more extended use of revolving furnaces. 

 The total production at the mine is at the rate of over 100,000 

 ounces of gold per annum. The impetus given to the barrel 

 chlorination process a few years ago seems, from the above facts, 

 to have spent its force. 



The Bulletin of the Kansas Experimental Station records 

 instances of the poisoning of cattle by eating the stalks of Indian 

 corn, from the very large amount of potassium nitrate which 

 I hey contain. 



Our attention has been drawn to two laborious investigations 

 by E. Mazelle, of the Trieste Observatory, recently presented to 

 the Vienna Academy of Science, relating to the daily and 

 yearly range of variability of temperature, and to the relations 

 between the usual mean value and the " most frequent " values 

 of temperature, as deduced from the records of fifty years, 

 1841-90. The difference between the mean and most frequent 

 values has been discussed by various authorities, notably by Dr. 

 I. Hann in the second edition of his " Climatolog>-." The ob- 

 servations for each month, or year, are grouped so as to show 

 how often a certain value, or interval of temperature occurs, and 

 from these a curve is drawn which differs, according to circum- 

 stances, from one showing the mean values, and, while not super- 

 ceding the latter, is of considerable interest for comparison with 

 it. For various interesting details we refer our readers to the 

 original papers. 



The third edition of M. Faye's " L'Origine du Monde' 

 (Gauthier-Villars, Paris) has lately been published. In this 

 volume M. Faye states and discusses various theories and beliefs 

 held as to the mode of the genesis of worlds, from the Mosaic 

 record to the views of Kant and Laplace, and of their successors. 

 Within the past ten years much work bearing upon the evolution 

 ' of worlds has been done. Long-exposure photographs of nebulce 



« have given astronomers more information upon cosmical genesis 



{ than all that was known before their era, and photographs of 



I spectra have enabled spectroscopists to arrange celestial objects 



in order from the youngest to the oldest. We naturally turned 

 to the new edition of M. Faye's book expecting to find the work 

 of recent years set down with the fulness which it deserves. But 

 we were disappointed. Instead of a picture of Dr. Roberts' 

 photograph of the Andromeda nebula, there appears a venerable 

 cliche which ought to be banished from every book that pretends 

 to represent astronomical knowledge of to-day. The same remark 

 applies to the picture and the spectrum of the Orion nebula, of 

 the spectrum of Sirius, and to most of those in the volume. When 

 the first edition of the book appeared, such illustrations might 

 have passed muster ; but in these days of abundant photographs 



and cheap process-blocks, there is no excuse for offending the 

 sight with them. We cannot see any difference between the 

 third edition of ^f . Faye's book and the first edition, as regards 

 illustration, and little difference as regards the text. 



The additions to the Zoological Society's Gardens during the 

 past week include a Persian Gazelle (Gazella siihgiitterosa,i) 

 from Persia, presented by Mr. F. Greswolde-Williams ; two 

 Polecats (Mustela piitorius, <J 9 ), British, presented by Mr. 

 A. H. Cocks ; a Yellow-fronted hmzzoni^Chrysotis oihrocephala) 

 from Cluiana, presented by Lieut. -General Arthur Lyttleton- 

 Annesley ; two West African 'Lo\e-BiTds (A^apornt's pullaria) 

 from West Africa, presented by Mrs. Otto Fell ; a Crowned 

 Duyker-Bok {Cephalophtis coronaius, 9 ) from West Africa, two 

 King Penguins (Aptenody/es pennanti) from the Macquari 

 Islands, purchased. 



Erratum. — In the article on "The Habits of the Cuckoo" 

 (p. 176), for Dr. Reh read Dr. Rey. 



OUR ASTRONOMICAL COLUMN. 



Hind's Variable Nebula. — Further confirmation of the 

 variability of the nebula N.G.C. 1555, discovered by Dr. Hind 

 in 1852, has been obtained by Prof, Barnard {Monthly Notices, 

 vol. Ivi. p. 66). It may be remembered that so recently as 

 February 1895, the nebula was an easy object in the Lick 

 telescope, while Struve's nebula, in the immediate neighbour- 

 hood, was absent, and the nebulosity round t Tauri was imper- 

 ceptible (Nature, vol. Hi. p. 180). Under the very best con- 

 ditions of observation in September last, however. Hind's 

 nebula seemed to have entirely vanished, although every means 

 was tried to see it. This appears to definitely prove that the 

 light of the nebula fluctuates, and it is therefore desirable that 

 the place of this object should receive careful attention, t Tauri 

 was involved in a small hazy nebulosity, but the definite nebula 

 in which it shone in 1890 did not exist four months ago. 



o Ceti. — The last two or three maxima of this well-known 

 variable star have occurred considerably later than the com- 

 puted times, and the present, or perhaps approaching, maximum 

 is similarly behindhand. Accordmg to the ephemeris in the Com- 

 panion to the Obseri'atory, there should have tjeen a maximum on 

 December 9, but on January 8, the star had barely reached 4th 

 magnitude. The star is now much more favourably situated for 

 observation than during several preceding maxima ; and, in view 

 of the irregularity to which reference has been made, it is 

 important that the magnitude should be recorded as frequently 

 as possible. Spectroscopic observations will also be valuable, 

 and it may not be out of place to suggest a special look-out for 

 bright lines of helium and the associated gases, as well as 

 observations of the varying relative brightness of the carbon 

 fluting slightly more refrangible than the b group of magnesium. 



Stellar Velocities with Objective Prism. — The great 

 advantages of the objective prism over the slit spectroscope for 

 photographing the spectra of stars have been abundantly 

 demonstrated, but hitherto the latter form of instrument has 

 been considered essential for precise determinations of velocities 

 in the line of sight. An adaptation of the objective prism for 

 the latter purpose is proposed by M. Desl&ndres (Observatory, 

 January). In the arrangement suggested, the collimator of an 

 ordinary spectroscope is placed in a direction perpendicular to 

 the rays proceeding from the star, and the light passing through 

 the slit from the comparison spark is reflected upon the objective 

 prism by a small totally-reflecting prism. The collimator, 

 objective prism, and photographic telescope, thus constitute a 

 complete slit spectroscope. With the aid of the auxiliary visual 

 telescope, the spectrum of the star is photographed with the 

 objective prism in the ordinary way, and during the exposure 

 the terrestrial spectrum is photographed nearly alongside that of 

 the star, the adjustments having been so made that lines of 

 equal refrangibility in the two spectra are in the same straight 

 line. The spectrum of a star with which a comparison of 

 velocity is desired, or may be that of the same star after an 

 interval, is then photographed adjacent to the first, with the 

 help of the visual telescope ; and another terrestrial spectrum is 

 photographed alongside the previous one, a different part of the 



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NO. 1368. VOL. 53] 



